A track machine utilizes chains entrained about a sprocket, rollers, one or more idlers, and a track roller frame. A motor or an engine drives the sprocket, which engages bushings of the chain to move the chain around the track roller frame, thereby propelling the machine in the desired direction.
Typically, the chain includes a master link joint that allows assembly and disassembly of the chain by coupling the ends of the chain at the master link joint. While a “master link joint” is available in many forms, one prevalent design includes two pairs of “master links” disposed on either side of the chain. Each master link includes two “half links”, including a “first half link” and a “second half link”. A pin, rod or cartridge couples the first half link of one master link to the first half link of the other master link. A bushing couples the second half link of one master link to the second half link of the other master link. The bushing also engages the sprocket. Threaded fasteners couple a shoe to all four half links of the two master links. Thus, a master link joint includes two master links, two first half links coupled together by a pin, rod or cartridge, two second half links coupled together by a bushing, and a shoe that is coupled to all four half links. A master link, on the other hand, includes a first half link and a second half link that are coupled together by the threaded fasteners used to couple the shoe to all four half links.
Although this type of master link joint is widely accepted, it suffers from durability problems. Specifically, the fasteners and half links may break and/or the threads within the individual half links coupled to the shoe may strip. In these situations, the master links of the chain may separate, leaving the machine inoperable and immovable. Additionally, when the threads of the threaded fastener strip, the entire master joint may require replacement.